Using genetic tools to investigate distribution and connectivity of two Sierra Nevada amphibians, Rana sierrae and Rana boylii
The Sierra Nevada yellow-legged frog has suffered large declines along it's range due to several factors including predation from introduced trout and the infectious disease Chytridomycosis.
My project focuses on using non-invasive genetic methods to understand populations and help inform management decisions concerning yellow-legged frogs in Plumas National Forest. There are several components to my project:
Environmental DNA Protocol Development
I'm developing an eDNA sampling protocol for Sierra Nevada yellow-legged frogs and foothill yellow-legged frogs. Our hope is that this protocol will be used to detect frogs around the forest. I've developed species assays to detect both yellow-legged frogs.
Sierra Nevada Yellow-Legged Frog and Elevation
Sierra Nevada yellow-legged frog are generally found in streams and lakes above 4500 feet, but may occur down to 3500 feet in northern part of range. However, there is some uncertainty about lower elevation records. We are using a combination of eDNA and genetic samples from mouth swabs of frogs to investigate if Sierra Nevada yellow-legged frogs are in fact occurring below 4500 feet.
The Sierra Nevada yellow-legged frog and foothill yellow legged frog overlap in parts of the Plumas. Similarities in appearance can lead to difficulty in identifying species. Biologist in the field have seen individuals with intermediate phenotypes and we are using genetic samples to investigate if the two yellow-legged frog species are hybridizing.
 Vredenburg, V.T., Knapp, R. A., Tunstall, T.S., Briggs, C.J., 2010. Dynamics of an emerging disease drive large-scale amphibian population extinctions. Proc. Natl. Acad. Sci. 107, 9689–9694.